Smart Sensors Use on the Rise

Dec 06, 2002—Dec. 6, 2002 - A few years ago, talk of miniaturized machines that could sense temperature, humidity or even analyze DNA sounded like science fiction. Today, the price of micro-electromechanical systems, or MEMs, has fallen dramatically, and companies are now putting them into everything from washing machines to cars.

An article in the November issue of Appliance Magazine by Daniela Carrillo, an industry analyst in Frost & Sullivan's Sensors Group, says sales of two common sensors – pressure sensors and accelerometers – are expected to rise 11 percent to $1.5 billion next year. That follows a 13 percent rise last year and a 5 percent increase this year.

Sales of MEMs in the appliance market are expected to rise 20 percent to $75 million next year. Carrillo attributes the increasing use of electronic sensors to the fact that the new solid-state devices are smaller, more reliable, consume less power and are smarter than their forerunners

Another big reason is the sensors are getting much cheaper. Carrillo told RFID Journal that an accelerometer used in an airbag has dropped from about $50 two years ago to about $10 today. Pressure sensors have fallen from $20 to $30 two years ago to $3 to $7 today.

The reason for the price drops is related to the economics of silicon. Developing sensors that can be integrated with the microchip is an expensive process. But once the process is complete and sales begin to pick up, duplicating the sensors reliably becomes cost-effective. As improvements in circuit design and fabrication techniques improve, the costs fall further.

In some cases, sensors are being tied to RFID devices to provide remote sensing capabilities. In the auto industry, for instance, both Texas Instruments and Philips Semiconductors have developed integrated RFID sensors for monitoring tire pressure.

"RFID hasn't had a huge impact on the sensor industry yet," says Carrillo. "Some applications people are looking at are in the automotive market, consumer electronics and the medical field for creating health monitoring systems."

The use of RFID sensors is being held back for many of the same reasons cited for the lack of growth in the conventional RFID market– the lack of standards, the high cost of the tags and the limited number of fully developed applications.

But things are beginning to change. A number of industry bodies are working on standards, and companies like Honeywell, Motorola and Texas Instruments are working on RFID MEM sensors for a variety of applications.

Carrillo says that RFID could further drive the use of electronic sensors in a few years. Inexpensive, thin-film batteries could also play a role in accelerating the use of RFID MEM sensors.